One embodiment of the current invention relates to a brassiere for supporting breasts of a woman. Breasts of young women tend to be protuberant whereas breasts of older women tend to be pendulous. Protuberant breasts are supported by fibrous tissue strands known as ligaments of Astley Cooper. When the ligaments of Astley Cooper become overstretched or atrophic, the breasts droop. The breast tissue itself does not have muscular support, the ligaments of Astley Cooper connect deep fascia at the base of the breast with overlying skin. It is the function of a brassiere to provide support for the breast tissue (acting in concert with the ligaments of Astley Cooper).
Back pain is the number one cause of disability in the United States and the world. Neck pain is number four. Global costs of back pain range between $250-$500 billion per year. Four out of five people will suffer a severe neck or back episode in their lives. There is a stronger propensity for it to be a woman.
Many women with larger breasts need support to reduce the discomfort or fatigue related to their breast size. Support is needed particularly when the woman dances or participates in physical and athletic events or the like. One approach has been merely to make thinner and smaller conventional brassieres, but this approach does provide sufficient support for some women with larger breasts.
As a result, women around the globe are suffering from spine pain, in part due to lack of support associated with their large, heavy breasts. The exact impact of the forces of the breast on the spine has just been assessed in a recent study using finite element assessments to evaluate the contribution of the size and weight of the breast to the forces seen by the spine. In a similar study finite element assessments were utilized to evaluate the forces seen in the cervical spine caused by the posture and position of the head.
As a result of the study, it was determined that women with larger breasts and increased body mass index may experience cervical, thoracic and lumbar spine pain, focused at the mid-thoracic levels (thoracic 6-8). However, force plate assessments showed significant stresses placed along the spine from the cervical 2 through lumbar 1. This pain is made worse by poor posture and the bone-weakening effects of age including menopause. Incorrectly sized bras also contribute to back spinal pain.
In addition to age, pregnancy and breast-feeding may present unique situations where the size, shape and forces of the breasts are independently and significantly fluctuating, presenting variable and modulating forces on the spine.
As women age, osteoporosis inherently weakens bone structures. This diminished bone substance leads to a decreased threshold for pain and fracture. Along with aging, especially post-menarche, women have hormonal changes that also weaken their bone structure. Osteopenia is weakening of the bone while frank bone loss is called osteoporosis. Spinal deformities such as excessive lumbar lordosis may place additional reactive forces into the thoracic spine, lowering the threshold for spine pain. Poor posture such as that caused by thoracic kyphosis contributes to inefficient weight distribution contribute to excessive pain. Scoliosis, another structural deformity, leads to inefficient and asymmetrical weight distribution on the spine from the right and left breast. To reduce pain and fatigue, balancing and diminishing breast forces to the spine becomes a critical factor.
Breast surgeries including amputation of one breast and augmentation of both breasts lead to conditions requiring separate and distinct force management of the right and left breast. Traumatic situations such as car accidents or injury on a job may lead to temporary and sometimes permanent pain generation by the spine. Balancing and diminishing breast forces to the spine may be a significant factor to reducing this pain or managing these conditions.
Structurally breasts cantilever outwardly from a wearer's chest. Conventional brassieres generally provide a panel on the wearer's back whence straps extend over the wearer's shoulders to hold up her breasts. Of course these panels tend to hold in the wearer's sides but they are situated on muscles on the back of the wearer's trunk and they tend to restrict her motion and her circulation. Right and left breasts undergo distinct and separate forces. Studies have shown that the impact of neck forces may contribute or cause back pain. Indeed neck pain; mid-back pain and lower back pain may all be caused by forces placed upon the neck, mid-back or lower back independently.
Movement of a women's chest below her breasts is quite limited compared with movement of her shoulders and movements of her back. The majority of movement below the breasts is caused by expansion and contraction of the rib cage resulting from breathing. Such movement is quite simple, being directed laterally across the chest.
The weight of the average breast weighs about 0.5 kilograms (1.1 lb.). According, it is estimated that in a typical woman, both breasts share about 8-10% of a woman's body fat. The density of fatty tissue is approximately 0.9 kg/l for all women.
If a breast cup is a hemisphere, its volume V is established by the following formula:
  V  =                              2          ⁢          π          ⁢                                          ⁢                      r            3                          3            ⁢      V        =                  π        ⁢                                  ⁢                  D          3                    12      Where r is the radius of the cup, and D is its diameter.
Alternatively, if the breast cup is manipulated for a hemi-ellipsoid geometry, then the received volume may be established by the following equation:
  V  =                              2          ⁢          π          ⁢                                          ⁢          abc                3            ⁢      V        ≈                  π        ×        cw        ×        cd        ×        wl            12      Where a, b and c are the three semi-axes of the hemi-ellipsoid, cw=breast cup width, cd=breast cup depth, and wl=length of wire.
As is generally known, the breast cup may include many different alternative configurations, but is generally hemispherical or hemiellipsoidial in configuration. Generally, the underwire experiences the greatest strain and provides the greatest influence on the characteristic shape for the breast cup. It therefore, would be beneficial to provide an improved underwire design brassiere support structure for properly supporting the desired breast and its particular volume and weight.
The same underwire dimension may be utilized for a plurality of cup sizes e.g. 36A, 34B, 32C, 30D. Because the same underwire may be used for varying breast cups it needs to have flexibility in its design characteristics for containing a variety of volumetric and weight differences.
In a report by McCunn he established that the reference numbers of underwire sizes are based upon a B cup bra. As an example based on the following chart, the underwire size 32 in the US is equivalent to a 32B cup and in the UK is equivalent to 30C, and 34A. As further provided in the chart below, that means that for an underwire size of 30 width carries a cup curvature diameter of 3-inch ⅚≈=≈9.7 cm and this diameter increases by ⅓ inch≈=≈0.847 cm per increased underwire size. These estimations may be used in volume and weight calculations for consumer-sized cups which may be found in brassiere stores catering to women with large breasts. Table 1, shown below, indicates the derivation of cup volume and breast weight determined for each breast.
TABLE 1Breast Volume and Weight CharacteristicsUnder-CupVolumeWeight wireDia-Of Oneof BothSizeBra Size - US SystemBra Size - UK SystemmeterCupBreasts3032A 30B 28C32A 30B 28C 9.7 cm240 cm30.43 kg (3 in 5/6)(0.51 US pt)(0.95 lb)3234A 32B 30C 28D34A 32B 30C 28D10.6 cm310 cm30.56 kg(4 in 1/6)(0.66 US pt)(1.2 lb)3436A 34B 32C 30D 28E36A 34B 32C 30D 28DD11.4 cm390 cm30.70 kg(4 in 1/2)(0.82 US pt)(1.5 lb)3638A 36B 34C 32D 30E38A 36B 34C 32D 30DD12.3 cm480 cm30.86 kg28F28E(4 in 5/6)(1.0 US pt)(1.9 lb)3840A 38B 36C 34D 32E40A 38B 36C 34D 32DD13.1 cm590 cm31.1 kg30F 28G30E 28F(5 in 1/6)(1.2 US pt)(2.4 lb)4042A 40B 38C 36D 34E42A 40B 38C 36D 34DD14.0 cm710 cm31.3 kg32F 30G 28H32E 30F 28FF(5 in 1/2)(1.5 US pt)(2.9 lb)4244A 42B 40C 38D 36E44A 42B 40C 38D 36DD14.8 cm850 cm31.5 kg34F 32G 30H 28I34E 32F 30FF 28G(5 in 5/6)(1.8 US pt)(3.3 lb)4444B 42C 40D 38E 36F44B 42C 40D 38DD 36E15.7 cm1,000 cm31.8 kg34G 32H 30I 28J34F 32FF 30G 28GG(6 in 1/6)(2.1 US pt)(4.0 lb)4644C 42D 40E 38F 36G44C 42D 40DD 38E 36F16.5 cm1,180 cm32.1 kg34H 32I 30J 28K34FF 32G 30GG 28H(6 in 1/2)(2.5 US pt)(4.6 lb)4844D 42E 40F 38G 36H44D 42DD 40E 38F 36FF17.4 cm1,370 cm32.5 kg34I 32J 30K 28L34G 32GG 30H 28HH(6 in 5/6)(2.9 US pt)(5.5 lb)5044E 42F 40G 38H 36I44DD 42E 40F 38FF 36G18.2 cm1,580 cm32.8 kg34J 32K 30L 28M34GG 32H 30HH 28J(7 in 1/6)(3.3 US pt)(6.2 lb)5244F 42G 40H 38I 36J44E 42F 40FF 38G 36GG19.0 cm1,810 cm33.3 kg34K 32L 30M 28N34H 32HH 30J 28JJ(7 in 1/2)(3.8 US pt)(7.3 lb)5444G 42H 40I 38J 36K 44F 42FF 40G 38GG 36H19.9 cm2,060 cm33.7 kg34L 32M 30N 28O34HH 32J 30JJ 28K(7 in 5/6)(4.4 US pt)(8.2 lb)5644H 42I 40J 38K 36L44FF 42G 40GG 38H 20.7 cm2,340 cm34.2 kg34M 32N 30O 28P36HH 34J 32JJ 30K 28KK(8 in 1/6)(4.9 US pt)(9.3 lb)5844I 42J 40K 38L 36M44G 42GG 40H 38HH 36J21.5 cm2,640 cm34.8 kg34N 32O 30P34JJ 32K 30KK(8 in 1/2)(5.6 US pt)(11 lb)6044J 42K 40L 38M 36N44GG 42H 40HH 38J 36JJ22.4 cm3,000 cm35.3 kg 34O 32P34K 32KK(8 in 5/6)(6.3 US pt)(12 lb)
Data from a recent finite element analysis study related to the impact of forces of the breast on the spine reflected in the table below, indicates the magnitude of forces generated by each breast upon the thoracic spine ranges between 8.5 pounds of force for underwire size 30 to 110 pounds of force for underwire size 60. All increments in between were reported in Newton and pounds of force.
TABLE 2Forces exerted upon spine by unsupported breastUnderwireWeight OfStressForcesForcesSizeBra Size-US SystemBra Size-UK SystemBoth Breasts(N/m{circumflex over ( )}2)(N)(lbf)3032A 30B 28C32A 30B 28C0.43 kg (0.95 lb) 26E03 N/m{circumflex over ( )}2 38 N8.543234A 32B 30C 28D34A 32B 30C 28D0.56 kg (1.2 lb) 35E03 N/m{circumflex over ( )}2 48 N 10.793436A 34B 32C 30D 28E36A 34B 32C 30D 28DD0.70 kg (1.5 lb) 55E03 N/m{circumflex over ( )}2 67 N 15.063638A 36B 34C 32D 30E 28F38A 36B 34C 32D 30DD 28E0.86 kg (1.9 lb) 78E03 N/m{circumflex over ( )}2 82 N 18.433840A 38B 36C 34D 32E 30F 40A 38B 36C 34D 32DD 30E 1.1 kg (2.4 lb) 95E03 N/m{circumflex over ( )}2102 N22.9328G28F4042A 40B 38C 36D 34E 32F 42A 40B 38C 36D 34DD 32E 1.3 kg (2.9 lb)119E03 N/m{circumflex over ( )}2126 N 28.3230G 28H30F 28FF4244A 42B 40C 38D 36E 34F44A 42B 40C 38D 36DD 34E 1.5 kg (3.3 lb)138E03 N/m{circumflex over ( )}2143 N 32.1432G 30H 28I32F 30 FF 28G32F 30FF4444B 42C 40D 38E 36F 34G44B 42C 40D 38DD 36E 34F 1.8 kg (4.0 lb)156E03 N/m{circumflex over ( )}2169 N 37.9932H 30I 28J32FF 30G 32FF 30G 28GG4644C 42D 40E 38F 36G 34H44C 42D 40DD 38E 36F 2.1 kg (4.6 lb)185E03 N/m{circumflex over ( )}2193 N 43.3832I 30J 28K34FF 32G 30GG 28H4844D 42E 40F 38G 36H 34I44D 42DD 40E 38F 36FF 2.5 kg (5.5 lb)227E03 N/m{circumflex over ( )}2235 N52.8332J 30K 28L34G 32GG 30H 28HH5044E 42F 40G 38H 36I 34J44DD 42E 40F 38FF 36G2.8 kg (6.2 lb)256E03 N/m{circumflex over ( )}2262 N58.8932K 30L 28M34GG 32H 30HH 28J5244F 42G 40H 38I 36J 34K44E 42F 40FF 38G 36GG 3.3 kg (8.2 lb)302E03 N/m{circumflex over ( )}2311 N69.9132L 30M 28N34H 32HH 30J 28JJ5444G 42H 40I 38J 36K 34L44F 42FF 40G 38GG 36H3.7 kg (8.2 lb)338E03 N/m{circumflex over ( )}2342 N76.8832M 30N 28O34HH 32J 30JJ 28K5644H 42I 40J 38K 36L 34M44FF 42G 40GG 38H 36HH4.2 kg (9.3 lb)375E03 N/m{circumflex over ( )}2386 N86.7732N 30O 28P34J 32JJ 30K 28KK5844I 42J 40K 38L 36M 34N44G 42GG 40H 38HH 36J4.8 kg (11 lb)449E03 N/m{circumflex over ( )}2452 N101.6132O 30P34JJ 32K 30KK6044J 42K 40L 38M 36N 34O44GG 42H 40HH 38J 36JJ5.3 kg (12 lb)476E03 N/m{circumflex over ( )}2489 N109.9332P34K 32KK
The next table reflects the additional forces of the breast on the spine with a torso angularly positioned at a 20 deg. forward posture.
TABLE 3Forces upon spine based upon poor postureUnder-AddedAddedwireStress reactionreactionSizeBra Size - US SystemBra Size - UK System(N/m{circumflex over ( )}2)forces (N)forces (lbf)3032A 30B 28C32A 30B 28C5.46E+05 5311.96N/m{circumflex over ( )}2(+40%)3234A 32B 30C 28D34A 32B 30C 28D1.05E+05 6715.11N/m{circumflex over ( )}2(+40%)3436A 34B 32C 30D 28E36A 34B 32C 30D 28DD1.65E+05 9421.09N/m{circumflex over ( )}2(+40%)3638A 36B 34C 32D 30E38A 36B 34C 32D 30DD2.34E+05 11525.8128F28EN/m{circumflex over ( )}2(+40%)3840A 38B 36C 34D 32E40A 38B 36C 34D 32DD2.85E+05 14332.130F 28G30E 28FN/m{circumflex over ( )}2(+40%)4042A 40B 38C 36D 34E42A 40B 38C 36D 34DD3.57E+05 17639.6632F 30G 28H32E 30F 28FFN/m{circumflex over ( )}2(+40%)4244A 42B 40C 38D 36E44A 42B 40C 38D 36DD4.14E+05 20045.0134F 32G 30H 28I34E 32F 30FF 28GN/m{circumflex over ( )}2(+40%)4444B 42C 40D 38E 36F44B 42C 40D 38DD 36E4.68E+05 23753.1934G 32H 30I 28J34F 32FF 30G 28GGN/m{circumflex over ( )}2(+40%)4644C 42D 40E 38F 36G44C 42D 40DD 38E 36F5.55E+05 27060.7434H 32I 30J 28K34FF 32G 30GG 28HN/m{circumflex over ( )}2(+40%)4844D 42E 40F 38G 36H44D 42DD 40E 38F 36FF6.81E+05 32973.9634I 32J 30K 28L34G 32GG 30H 28HHN/m{circumflex over ( )}2(+40%)5044E 42F 40G 38H 36I44DD 42E 40F 38FF 36G7.68E+05 36782.4634J 32K 30L 28M34GG 32H 30HH 28JN/m{circumflex over ( )}2(+40%)5244F 42G 40H 38I 36J44E 42F 40FF 38G 36GG9.06E+05 43597.8834K 32L 30M 28N34H 32HH 30J 28JJN/m{circumflex over ( )}2(+40%)5444G 42H 40I 38J 36K 44F 42FF 40G 38GG 36H1.01E+06 479107.6434L 32M 30N 28O34HH 32J 30JJ 28KN/m{circumflex over ( )}2(+40%)5644H 42I 40J 38K 36L44FF 42G 40GG 38H 1.13E+06 540121.4934M 32N 30O 28P36HH 34J 32JJ 30K 28KKN/m{circumflex over ( )}2(+40%)5844I 42J 40K 38L 36M44G 42GG 40H 38HH 36J1.35E+06 633142.2634N 32O 30P34JJ 32K 30KKN/m{circumflex over ( )}2(+40%)6044J 42K 40L 38M 36N44GG 42H 40HH 38J 36JJ1.43E+06 685153.934O 32P34K 32KKN/m{circumflex over ( )}2(+40%)
Improperly fitted brassieres may be a significant factor of thoracic spine pain. The weight of the supported breasts bears mainly on the thoracic spine where horizontal and vertical force components are directed. It would therefore be beneficial to reduce the forces exerted upon the thoracic spine and to the extent possible isolate the vertical and horizontal forces from each other.
In addition, breast sizes can fluctuate depending on the body fluctuations. For example, some breasts vary in size daily, weekly, monthly and yearly based on periodic biological fluctuations due to the changes of estrogen and progesterone in a women's menstrual cycle. Pregnancy and associated breast-feeding present unique situations where the size, shape and forces of the breasts are independently and significantly fluctuating, presenting variable and modulating forces on the spine. Additionally, breast size and shapes can vary widely as the person ages, changes weight or size. Therefore, there exists a need for a modulating brassiere support structure which allows for modulation, contraction or elongation along each of the three axes.
A standard brassiere currently is not designed to handle the varying load caused by significant breast changes which may exist statically or present changes that occur over time. A standard brassiere may not be designed to handle the additional breast load and may fail based on varying breast sizes in either or both breasts. When a standard brassiere fails, it may cause additional stress and strain on the thoracic spine. It therefore, would be beneficial to provide a dynamically adjustable, properly fitted brassiere which allows for adjustment of vertical and horizontal forces through a multiple support shoulder structure to help reduce the pain.
When considering all forces generated divided by the actual weight of the breasts, the magnification factor is approximately 10×. It is interesting that the smaller underwire sizes (30 and 32) representing smaller breasts displayed a 9× (9× more force to weight). Underwire sizes 34 through 52 showed approximately a 10× force to breast weight ratio. The largest underwire sizes 54-60 demonstrated approximately 9×.
Standard brassieres do not provide proper support to avoid thoracic spine pain based on the range of forces caused by varying breast sizes. Using the American bra sizing system a woman with size 36 H would expect 52 pounds of force on the spine (for both breasts) while with weight loss she may achieve a 36D with associated 28 pounds of force for both breasts a reduction of 24 pounds upon the spine or an increased load of 24 pounds, if she gains the weight.
With an improved brassiere support structure, a reconstructive surgeon may be able to better plan breast sizing for patients based on desired thoracic spinal loads. Taking a woman from an American sized 32C (15 lbf) to an augmentation and enlargement to a 32E (23 lbf) may lead to an increase of 8 lbf. Enlarging 34B breasts (18.4 lbf) to a 34 F (32.1 lbf) result in an increase of approximately 14 lbf on the spine.
In addition to a brassiere, there are many applications where a user is required to carry a significant load for a substantial period of time, including military personnel, hikers and backpackers. Due to the weight which must be supported over an extended period, many of the same difficulties need to be addressed in other applications. For example, backpacks may carry heavy loads for significant periods while traversing a variety of terrains. In some cases, these loads are carried improperly for example at a forward angle. It would be beneficial to disperse the weight of any supported load through multiple straps each of which is adjustable and adapted for spreading the supported load over a larger portion of the torso. Many backpacks utilize a hip belt for strapping the backpack to the wearer. However, in some cases, these hip belts are improperly positioned or fail to properly support the carried load. It therefore would be beneficial to provide an improved support structure with vertically extending members between the upper body engaging member and a lower body engaging member to disperse the unidirectional tensioning load associated with the wearer's chest, dampening the moving or shifting load.
For these reasons an improved chest support structure is desired to reduce back strain and provide additional support far better than a traditional brassiere or other chest support which provides improved counter balance of the various opposing forces than in conventional chest support structures. Therefore, it would be beneficial to employ an improved support structure in these other applications like a backpack.
In general, some chest support structures utilize a shoulder strap. However, the current shoulder strap typically utilizes a singular strap which must carry the entire weight of the entire load forcing the shoulder straps into the sensitive shoulder region of the wearer causing pain and discomfort, failing to properly support the carried load and causing stress and strain upon the wearer. It therefore would be beneficial to provide an improved hyperbolic support structure with a plurality of vertical structures to reduce the weight and strain upon the back. The vertical structures may also be adjusted for improved alignment vertically and horizontally as the vertical structures are spaced from each other so that the weight of the supported load can be spread out collectively by the vertical structures to reduce the stress and strain associated with any single structure and hence upon the wearer, spreading the forces along the torso.
Based on the foregoing, there is a need for an improved chest support structure which addresses some of the aforementioned problems, including reducing the stress and strain on the thoracic spine caused by presently available, inadequate chest support structures, like brassieres and backpacks.